Exporting My Map to Garmin GPS

I created a specific map in "My Maps" google, but I can't figure out how to export the locations saved in "my map" to my Garmin 2595LM. I have it connected via USB, but where is the export button. Can this be done? I can pull up "my map" on my Iphone, but I'd much rather have the coordinates in my GPS. Please help.